* Introduced `MKVToolNix` and `mkvpropedit` binaries to the project.
* Updated the environment check to include required status for dependencies.
* Enhanced the `Tracks` class to raise an error if `MKVToolNix` is not found.
* Modified the `_apply_tags` function to utilize the `mkvpropedit` binary from the binaries module.
* Introduced `SubtitleCodecChoice` to allow selection of subtitle codecs with support for enum names, values, and common aliases.
* Updated `--sub-format` option in `dl.py` to utilize the new `SubtitleCodecChoice`.
